8061  ltZ  -NVP  IVd 
•A  'N  ' 


PERCEPTION 


1914 


STATE    NORMAL    SCHOOL 
FITCHBURG,  MASSACHUSETTS 


PE  RC  EPTION 


BY  THE  CLASS  OF  NINETEEN 
HUNDRED  FOURTEEN  OF  THE 
STATE  NORMAL  SCHOOL  AT 
FITCHBURG,  MASSACHUSETTS 


WITH  AN  INTRODUCTION 
BY     E.     A.     KIRKPATRICK 


FITCHBURG  MASSACHUSETTS,  MCMXIV 
PUBLISHED  BY  THE  CLASS,  AND  PRINT- 
ED BY  THE  PRACTICAL  ARTS  PRESS 


L  B  it 


Introduction 

This  pamphlet  was  begun  by  the  vote  of  the  class  after  studying 
those  prepared  by  previous  classes.^  The  subject  was  selected,  out- 
lined, discussed,  and  the  matter  formulated  the  first  year.  Each 
member  of  the  class  wrote  on  most  of  the  topics,  and  nearly  all  served 
on  some  committee  appointed  to  select  and  arrange  the  best  of  the  ma- 
terial supplied  by  the  class.  In  the  second  year  the  manuscript  was 
revised  by  committees,  approved  by  the  class,  and  seen  through  the 
press  by  an  editorial  committee.  The  cover,  representing  the  class 
flower,  was  selected  from  several  designs  prepared  by  members  of 
the  class.  The  total  recitation  time  spent  probably  amounted  to  twenty 
or  twenty-five  periods. 

E.     A.     KlRKPATRICK, 

Head  of  the  Department  of  Psychology  and  Child  Study. 


371919 


PERCEPTION 


Introduction 

So  gradually  and  so  naturally  does  the  power  of  perception  come 
to  us  that  we  do  not  stop  to  think  how  wonderful  it  is  until  psychology 
paves  the  way.  To  find  out  how  perception  is  brought  forth  people 
should  be  watchful  and  observant. 

A  normal  student  was  once  asked  to  formulate  a  definition  of 
perception  without  direct  reference  to  any  text  book.  The  propo- 
sition confronting  her  seemed  difficult.  Her  mind  was  busily  engrossed 
with  this  problem  on  her  homeward  journey  from  the  day's  recita- 
tions. As  she  approached  the  doorstep,  her  small  sister,  who  was 
busily  engaged  in  play  in  the  middle  of  the  floor,  called  out  her  name. 
She  had  recognized  her  footsteps.  On  entering  the  house,  her  little 
sister  remarked  about  the  muddy  condition  of  her  rubbers  and  asked 
if  it  had  been  raining.  Then  suddenly  she  sniffed  and  ran  off  to  the 
kitchen  to  attend  to  some  burning  food. 

The  student  had  been  at  home  just  three  minutes,  and  within  this 
time  her  little  sister  had  been  making  a  number  of  quick  observations. 
The  student  at  once  looked  upon  them  as  material  which  might  prove 
helpful  as  a  foundation  for  her  work,  and  she  readily  analyzed  them. 
"My  footsteps,"  she  said,  "were  recognized  because  of  previous 
knowledge  of  their  sound.  The  fact  that  I  was  in  the  habit  of  reaching 
home  at  the  same  hour  each  day,  together  with  the  familiar  sound  of 
my  footsteps  helped  my  sister  to  recognized  me.  Through  sight  she 
was  able  to  tell  that  there  had  been  a  recent  rainstorm.  The  sense  of 
smell  brought  to  her  mind  the  truth  of  burning  substance." 

The  outgrowth  of  this  analysis  was  the  following  definition,  which 
proved  to  be  adequate  in  its  nature:  "Perception  is  the  power  to  ac- 
quire knowledge  through  the  aid  of  the  senses." 

In  preparing  our  pamphlet  we  have  taken  as  a  basis  for  thought 
the  preceding  definition.  Our  aim  has  been  to  give  our  readers  a 
clear  and  thorough  knowledge  of  this  particular  subject.  The  method 


of  procedure  has  been  guided  by  the 'thoughts  suggested  in  the  defini- 
tion. In  short,  we  have  endeavored  to  develop  ideas  of  perception 
through  the  aid  of  selected  topics,  namely : 

1 — Sensory  and  motor  factors;  2 — Mental  factors  relating  to  perception:  3 — 
Illusions;  4— Space  perception;  5— Conditions  favoring  perception;  6— Develop 
ment  of  perception;  7 — Apperception. 


Sensory  and  Motor  Factors  in  Perception 

The  importance  of  sensory  and  motor  factors  in  perception  is 
clearly  shown  by  the  following  examples. 

Mary  was  blindfolded  on  Hallowe'en  and  asked  to  touch  va- 
rious things  on  a  table  and  tell  what  they  were.  With  the  exception  of 
one  or  two  objects  she  was  able  to  tell  what  they  were  —  a  stone,  a 
stuffed  wet  glove. 

Let  us  consider  the  facts  involved  in  the  perception  of  the  stone. 
The  stone  was  felt  by  moving  and  pressing  the  ringers  against  the 
object.  The  feeling  caused  by  the  pressure  of  the  fingers  upon  the 
stone  is  called  a  sensation.  Sensation  is,  therefore,  feeling  produced 
by  contact  between  some  object,  liquid,  gas,  and  some  sense  organ. 

The  stone  felt  hard  and  smooth,  that  is,  the  pressure  was  unyield- 
ing and  even.  Where  such  decision  is  reached  in  the  mind,  percep- 
tion takes  place.  Perception  represents  sensation,  plus  a  certain 
amount  of  additional  activity. 

There  are  several  factors  involved  in  the  above  illustration.  The 
fingertips  felt  the  stone  through  the  aid  of  end  organs,  nerves,  and 
nerve  cells,  in  the  brain.  Without  these  three,  no  sensation  or  per- 
ception is  received.  The  brain  acts  according  to  the  sensations  re- 
ceived. If  the  fingers  come  in  contact  with  a  hot  radiator,  the  brain 
sends  a  message  to  the  fingers  ordering  removal. 

The  different  senses,  touch,  sight,  hearing,  smell,  taste,  motor, 
and  organic,  act  to  a  large  extent  as  protectors  of  the  body.  The 
eye  and  ear  are  the  most  important  sense  protectors  of  the  body. 
The  sight  and  sound  of  an  approaching  automobile  warns  the  person 
as  he  is  about  to  cross  the  street  to  wait  until  the  machine  has  passed. 
The  ear,  in  such  a  case,  often  causes  one  to  look  for  theautomo  bile. 
The  eye  enables  one  to  tell  more  accurately  how  near  the  machine  is, 


and  at  what  speed  it  is  approaching.  If  the  eye  and  ear  gain  the 
perception  that  the  machine  is  not  approaching  near  at  high  speed,  we 
may  judge  the  way  safe  for  crossing  at  that  time.  The  eye  often 
serves  to  warn  one  against  improper  food.  The  eye  prevents  many 
accidents,  as  falling  down  stairs,  burning  one's  self,  etc.  The  value 
of  the  ear  would  not  be  so  important  did  it  not  call  the  eye,  as  an  as- 
sistant. 

As  knowledge  is  gained  through  the  senses,  the  eye  and  ear  are  the 
sense  organs  most  used  in  gaining  an  education.  Without  the  eye, 
reading,  for  the  normal  person,  is  impossible.  Lectures  and  conver- 
sations, which  are  such  important  factors  in  education,  are  made  pos- 
sible by  the  ear,  and  more  vivid  and  interesting  by  the  eye  which  sees 
the  facial  expressions  of  the  speaker.  Thus,  the  pleasures  gained 
through  the  senses  are  generally  quite  well  appreciated.  Many  pleas- 
ures are  received  through  the  senses  of  sight  and  hearing. 

The  senses  aid  one  another  to  a  great  extent,  thus  increasing  their 
general  usefulness  to  the  body  and  mind.  The  loss  of  a  single  sense, 
even  with  other  senses  highly  developed,  leaves  some  trace  of  incom- 
plete mental  development. 

Touch 

An  experiment  was  tried  with  a  hairpin  on  a  blind-folded  student. 

The  student  was  asked  to  tell  when  he  felt  but  one  point  of  the 
hairpin.  The  experiment  was  tried  on  the  fingers  several  times,  and 
in  every  case  the  two  points  were  felt  until  they  were  less  than  a  six- 
teenth of  an  inch  apart.  When  the  experiment  was  tried  on  the 
neck,  the  two  points  had  to  be  separated  a  half  inch  before  they  were 
distinguished.  The  fingers  were  far  more  sensitive  to  the  experiment 
than  the  neck.  This  is  due  to  the  fact  that  the  nerve  ends  are  located 
more  thickly  in  the  fingers  than  in  the  neck. 

The  nerve  endings  of  the  sense  of  touch  are  located  most  thickly 
in  the  tip  of  the  tongue,  the  lips,  and  the  finger  tips.  These  sensitive 
spots,  you  will  notice,  are  the  most  movable  parts  of  the  body.  The 
sensitiveness  of  these  organs  is  due  to  the  muscular  movements  of  the 
organs,  to  experience,  and  to  the  thickness  of  the  end  organs. 

The  sensations  brought  about  by  pressure  vary  to  quite  an  extent. 
The  varying  degrees  of  pressure  bring  about  perception.  The  per- 
ception of  hardness  and  softness  depends  upon  intensity  of  pressure, 


while  perceptions  of  roughness  and  smoothness  are  caused  by  variations 
of  pressure.  The  pressure  of  a  polished  surface  is  even,  therefore  we 
perceive  that  the  surface  is  smooth.  The  pressure  of  sandpaper  upon 
the  fingers  is  uneven,  therefore  perception  says  that  sandpaper  is 
rough.  Yielding  surface,  as  cotton  batting,  is  perceived  as  soft. 

Touch,  as  we  ordinarily  think  of  it,  depends  upon  pressure  plus 
other  movements.  If  we  move  our  fingers  over  a  velvet  surface,  we 
gain  a  much  clearer  idea  of  the  texture  or  quality  of  the  velvet  than  if 
we  simply  lay  the  fingers  upon  the  surface  We  need  only  to  watch 
people  at  counters  as  they  buy  things  to  see  to  what  a  great  extent  the 
muscular  movements  of  the  fingers  aid  the  sense  of  touch. 

Excessive  stimulation  by  pressure  causes  pain.  If  the  hand  be 
brought  down  hard  upon  the  surface  of  a  table,  pain  is  the  result  of 
the  act.  In  the  case  of  a  needle,  slight  pressure  is  painless,  while 
hard  pressure  is  the  opposite. 

Heat  and  cold  stimuli  are  received  through  the  skin.  Cold  often 
carries  with  it  the  perception  of  dampness.  A  cold,  dry  cloth  is  often 
felt  to  be  cold  and  damp.  Whether  an  object  be  perceived  as  wtrt  or 
dry  is  largely  determined  by  temperature.  If  water  be  colder  than  the 
surrounding  air  it  is  distinguished  as  cold  water  easily.  But  if  the 
temperature  be  like  the  temperature  of  the  air,  perception,  by  the 
skin,  is  somewhat  baffled. 

The  following  experiment  was  tried  on  a  blindfolded  student: 
the  subject  was  touched  on  different  parts  of  the  hand  and  face  with 
a  pencil.  On  some  places  the  lead  felt  cold,  on  others  warm,  thus 
causing  the  student  to  think  that  she  was  touched  with  different  objects. 

The  feeling  of  the  varying  temperatures  is  due  to  the  fact  that 
there  are  hot  and  cold  spots  on  the  body  which  respond  to  heat  and 
cold  sensations  especially. 

This  sense  is  of  great  value,  not  only  to  man,  but  to  animals  as 
well.  All  animals  possess  this  sense,  and  many  of  the  lower  animals 
could  not  live  without  it.  The  amoeba,  for  example,  closes  upon  that 
which  he  feels  is  fit  for  assimilation,  and  shrinks  from  that  which  does 
not  appeal  to  his  sense  of  touch. 

Thus  it  has  been  shown  that  the  sense  of  touch  serves  as  a  valu- 
able protector,  as  an  aid  to  the  other  senses,  and  as  a  source  of  knowl- 
edge and,  to  the  child  especially,  of  pleasure. 


Sight 

A  student,  on  retuning  to  her  room  after  her  first  visit  to  another 
suite  was  asked  by  her  roommate,  "How  is  the  suite  furnished?" 
The  girl  questioned  was  able  to  give  a  general  description  as  to  size, 
form,  and  color  of  the  suite  and  its  furnishings.  All  this  was  per- 
ceived through  the  eye.  Primarily  size  and  form  perceptions  are  re- 
ceived through  the  sense  of  touch,  but  this  is  largely  done  away  with 
after  early  childhood.  The  child  is  often  deceived  in  regard  to  solids  or 
rounded  objects  and  needs  to  feel  of  them  to  understand  their  real  shape 
and  size.  Light  and  color  perceptions  are  received  through  the  eye 
alone.  Color  perceptions  are  produced  by  the  vibrations  of  ether 
waves.  The  varying  vibrations  produce  colors  and  their  many  shades 
and  hues.  A  combination  of  all  colors  produce  white  and  light. 

The  movability  of  the  eye  givff§  one  power  to  receive  sensations 
and  perceptions  more  rapidly.  Thus  in  reading  a  book,  one  would 
naturally  raise  the  eyes,  at  least  in  reading  at  the  top  of  the  page,  and 
lower  them  at  the  bottom  of  the  page.  With  out  moving  the  eye 
there  is  quite  a  range  in  which  one  may  perceive.  For  example,  one 
student  writes,  'I  am  now  facing  a  wall  on  which  I  can  see  several 
pictures.  But  besides  the  wall  I  can  see  out  of  a  window  which  is 
on  my  right.  By  merely  moving  the  eyeballs,  1  can  see  out  of  an- 
other window  which  is  at  right  angles  with  the  wall.  If  I  move  my 
head  I  can  see  more  easily  out  of  the  window."  The  movability 
of  the  head  and  body  greatly  aids  the  eye.  By  movements  of  the 
head  and  body,  a  bird  may  be  followed  as  it  otherwise  would  not  be 
possible. 

Objects  may  be  placed  in  a  better  range  for  the  eye.  A  reader 
changes  the  position  of  his  book  or  paper  as  he  reads,  so  that  he  may 
perceive  most  easily  and  rapidly.  Various  changes  of  position  affect 
the  perceptions  of  the  eye.  For  instance,  a  plate  appears  oval  in  some 
positions  and  round  in  others. 

In  very  few  animals  does  sight  play  as  important  a  part  as  in  man. 
The  senses  of  touch  and  hearing  are  more  valuable  to  animals,  though 
without  sight  most  animals  would  not  be  so  quick  in  their  movements. 

This  sense  is  a  wonderful  gift  to  man.  However,  if  a  person  has 
never  been  blessed  with  it,  he  does  not  feel  the  loss  to  such  an  extent 
as  one  who  has  had  it,  and  has  later  been  deprived  of  it.  His  loss  is 
partly  made  up  by  the  keenness  of  his  other  senses. 


Hearing 

In  a  parlor  were  three  girls.  One  was  playing  the  piano,  the 
other  two  were  talking.  Suddenly  a  strong  gale  came  in  through  the 
open  window  and  knocked  over  a  flower  pot.  A  crash  was  heard. 
This  may  illustrate  the  different  kinds  of  sound  which  may  strike  the 
ear  drum.  The  first,  that  of  playing  the  piano,  may  be  called  music, 
because  music  may  be  called  rhythmical  sound  which  is  pleasing  in 
pitch  and  key.  The  second,  speaking,  is  unrhythmical  sound,  which 
may  vary  in  pitch  and  tone.  The  noise  produced  by  the  crashing  of 
the  flower  pot  is  still  another  illustration  of  sound. 

Helen  Keller  can  perceive  music  by  touching  her  fingers  to  the 
instrument  being  played,  showing  that  it  is  possible  to  receive  vibra- 
tions through  the  nerves  of  the  fingers  as  well  as  through  the  ear  drum. 

Experiments  have  proven  that  one  may  perceive  very  accurately 
through  the  ear  drum  alone.  After  a  deal  of  experience,  a  person 
accustomed  to  the  sound  of  a  train  whistle  can  recognize  the  whistle 
of  any  train  at  a  great  distance  and  can  estimate  that  distance  by  the 
degree  of  intensity  of  sound.  This  is  aided  to  a  great  extent  by 
movement.  If  we  do  not  hear  distinctly  we  will  invariably  move  our 
body  into  a  position  where  we  may  hear  better.  Watch  a  person  try- 
ing to  locate  a  sound.  Does  he  not  move  his  head  and  body  so  that 
he  may  measure  sound  in  various  ways  and  locate  it? 

This  sense  of  hearing  has  a  very  important  place  in  our  educa- 
tion, pleasure,  and  association  with  other  people.  We  are  able  to  con- 
verse quickly,  to  listen  to  lectures,  music,  etc.  By  the  ear  we  are 
inspired  to  read  and  study,  and  in  other  ways  to  develop  our  mental  fac- 
ulties. We  may  say  hearing  is  the  most  important  sense  in  the  so- 
cial world,  for  even  though  one  may  be  blind,  if  he  can  hear  and 
speak  he  may  gain  a  great  deal  from  people  with  whom  he  comes  in 
contact.  A  deaf  and  dumb  person  does  not  know  what  other  people 
are  talking  about,  and  cannot  join  the  happy  association  of  convers- 
ing with  them. 

Smell 

One  student  writes:  "In  passing  through  the  corridor  of  the 
normal  school,  I  often  inhaled  agreeable  odors  of  food  that  were  be- 
ing cooked.  It  was  not  until  further  approach  to  the  kitchen  of  the 

10 


dormitory  that  I  was  able  however  to  distinguish  what  it  was  that  was 
being  prepared." 

Smell  is  the  sense  by  which  we  perceive  odors.  Odors  are  classi- 
fied as  being  agreeable  and  disagreeable.  It  is  impossible  to  state  how 
many  qualities  of  smell  the  nose  can  distinguish.  Odors  are  results 
of  vapors  or  gases  present  in  the  atmosphere.  When  we  open  an 
orange  we  inhale  the  gas  which  is  given  off,  and  can  very  easily  tell  what 
it  is.  In  some  animals,  and  even  people,  the  sense  of  smell  is  very 
acute,  while  in  others  it  is  not  as  keen.  It  may  be  highly  developed, 
especially  where  there  is  a  deficiency  in  other  senses. 

A  girl  working  in  a  drug  store  said  that  at  first  the  odors  gave 
her  a  headache.  Now  she  has  become  so  accustomed  to  them  that 
she  does  not  mind  their  strong  smell.  Therefore  the  first  scent  of 
anything  seems  always  the  most  acute.  We  recognize  a  pineapple  by 
its  delicious  smell  even  before  we  taste  it. 

The  delicacy  of  this  sense  is  much  greater  in  many  of  the  lower 
animals  than  in  man.  To  the  animal  smelling  is  believing.  Smell  to 
many  animals  is  like  sight  to  us.  The  sense  of  odors  gives  informa- 
tion as  to  the  character  of  food  and  drink,  and  to  the  purity  of  the  air. 

If  a  man  were  to  enter  a  room  filled  with  gas,  and  he  were  not 
able  to  smell  it,  he  would  very  likely  stay  in  the  room  long  enough  to 
be  overcome,  or  even  suffer  death,  proving  that  smell  is  a  very  impor- 
tant sense.  People  who  have  been  deprived  of  it  are  the  only  ones 
who  can  realize  what  a  great  loss  it  is. 

Taste 

A  piece  of  sweet  chocolate  was  placed  on  the  tongue  of  a  student 
who  held  her  nostrils  so  that  no  air  could  be  admitted. 

Do  you  think  she  knew  what  it  was  she  was  tasting?  The  only 
impression  she  got  was  that  a  foreign  or  new  substance  came  in  con- 
tact with  the  mucous  membrane  of  her  tongue.  The  quality  she 
perceived  by  this  special  sense  of  taste  was  that  of  sweetness.  But  as 
soon  as  she  was  aided  by  the  sense  of  smell  she  could  perceive  that  it 
was  chocolate,  and  not  peppermint. 

So  long  as  the  chocolate  remained  solid,  no  matter  how  bitter  a 
brand  of  chocolate  it  might  be,  it  would  be  impossible  to  perceive  the 
taste  until  it  was  allowed  to  melt.  After  any  substance  becomes  a 
liquid  its  taste  may  easily  be  distinguished.  The  qualities  in  taste  are 

11 


bitter,  sweet,  salt  and  sour.  Moving  the  object  from  one  part  of  the 
mouth  to  another  also  aids  in  perceiving  the  taste.  It  determines  the 
grade  of  food  as  well  as  the  taste  of  it.  By  moving  a  piece  of  apple 
from  one  part  of  the  mouth  to  another  we  may  feel  its  crispness. 

The  different  parts  of  the  tongue  respond  to  different  tastes.  The 
sides  of  the  tongue  are  particularly  responsive  to  sour,  the  tip  of  the 
tongue  to  sweet  and  to  salt,  and  the  center  is  generally  senseless  to  taste. 
Some  substances,  such  as  saccharine,  produce  one  taste  in  one  part  of 
the  mouth  and  a  different  taste  in  another  part.  This  crystalline  sub-- 
stance, which  is  a  form  of  uncrystallized  sugar,  is  sweet  to  the  tip,  and 
bitter  to  the  base  of  the  tongue.  All  these  facts  are  easy  to  explain, 
provided  there  are  taste  cells  which  always  respond,  with  a  special 
sensation. 

Organic  Sensations 

To  the  sensations  mentioned  so  far  must  be  added  those  which 
come  from  the  internal  organs  of  the  body.  Hunger,  thirst,  and 
nausea  are  sensations  perceived  from  the  stomach.  From  the  heart, 
lungs  and  other  organs  come  numerous  sensations  which  play  an  im- 
portant part  in  making  up  the  feeling  tone  of  our  lives. 


Mental  Factors  in  Perception 

There  are  other  factors  which  aid  perception,  besides  the  sensory 
and  motor  factors  just  discussed.  We  will  try  to  show  by  the  follow- 
ing illustrations  what  these  factors  are : 

Knowledge 

A  little  girl  who  had  been  away  visiting  returned  home  and  said, 
"Oh,  mother,  when  I  saw  the  electric  car,  I  knew  what  it  was  right 
off.  No  one  told  me."  How  did  this  little  girl,  who  had  never 
seen  an  electric  car,  recognize  it?  Her  parents  had  given  her  a  de- 
scription of  it.  With  this  knowledge  she  was  able  to  recognize  it 
instantly. 

Memory 

A  little  child  of  three,  although  told  repeatedly  not  to  touch  the 
hot  stove,  did  so,  and  burned  his  fingers.  Whenever  he  went  near  the 
stove  after  that  he  always  said,  "No  touch,  burn  baby's  ringers." 

12 


He  remembered  his  past  experience,  and  was  able  through  this  mem- 
ory to  make  his  perception  more  accurate  than  it  could  have  been 
under  other  circumstances. 

Habit 

One  day,  a  class  of  normal  school  students  were  confronted  for 
an  inslant  with  a  card  on  which  were  found  many  of  the  letters  found 
in  the  word  Fitchburg.  They  were  printed  in  the  following  order: 
Fetchbhurg.  Glancing  at  it  quickly,  nearly  all  of  the  pupils  called  it 
Fitchburg.  How  was  this  to  be  accounted  for?  Without  a  doubt, 
every  pupil  knew  that  those  letters  did  not  spell  Fitchburg.  The  only 
way  it  can  be  accounted  for  is  that  because  the  pupils  had  given  a  word 
this  name,  several  times,  which  bad  the  same  general  appearance. 
Through  repetition,  it  had  become  a  habit  and  was  finally  perceived 
without  any  thinking. 

Conceptions 

One  day  the  normal  school  class  observed  a  third  grade  geography 
lesson  on  Havana,  Cuba.  It  was  a  review  lesson  and  the  children 
were  questioned  about  the  Columbia  Cathedral.  They  had  been  told 
about  the  tablet  on  which  was  written  a  memorial  to  Columbus. 
When  a  little  boy  was  asked  what  interesting  thing  this  cathedral  con- 
tained, he  said,  "a  pill."  The  child's  only  knowledge  or  conception 
of  a  tablet  was  a  pill.  If  he  had  had  more  knowledge  on  the  subject 
his  perception  would  have  been  more  accurate. 

Imagination 

As  the  girls  left  the  observation  class,  Mary  Brown  and  her  friend 
became  engaged  in  an  interesting  conversation.  "Oh,  Louise,  the 
strangest  thing  occurred.  I  received  a  letter  from  cousin  Edith  a 
week  ago.  She  told  me  that  she  had  purchased  a  new  party  dress 
while  in  New  York.  In  a  later  letter,  I  asked  her  to  describe  it 
to  me,  but  she  refused,  saying  that  she  would  show  it  to  me  when 
I  called  at  her  house.  Immediatly  I  began  to  imagine  the  color  and 
make  of  the  dress.  To  my  surprise,  when  I  beheld  the  dress,  I 
found  that  my  imagination  had  enabled  me  to  picture  it  almost 
exactly. ' ? 

13 


Inference 

During  the  next  recitatation  the  fire  gong  sounded.  All  of  the 
pupils  immediately  inferred  that  this  was  a  fire  drill,  and  passed  out  of 
the  building  quietly.  By  drawing  such  an  inference  quick  percep- 
tions were  obtained.  If  no  inferences  were  drawn  the  fire  drill  would 
have  failed  in  its  purpose. 

Association 

About  an  hour  after  Mary  reached  home,  she  decided  to  have 
ginger  bread  and  whipped  cream  for  supper.  She  soon  had  the  ginger 
bread  in  the  oven.  About  fifteen  minutes  later  when  she  opened  the 
oven  door,  she  found  much  to  her  dismay  that  her  ginger  bread  had 
failed  to  rise.  Her  mother  asked  her  which  dish  she  got  the  soda  out 
of.  Mary  said,  "the  blue  dish."  She  was  then  told  that  she  had 
put  in  cream  of  tartar  instead  of  soda.  Both  the  cream  of  tartar  and  the 
soda  looked  alike  and  Mary  could  not  tell  the  difference.  Her  mother 
knew  the  difference  because  she  associated  the  blue  dish  with  the  cream 
of  tartar  and  the  white  dish  with  the  soda.  If  Mary  had  associated 
her  ideas  of  the  cream  of  tartar  with  some  definite  thing,  she  would 
have  had  a  correct  perception  of  it  and  would  not  have  spoiled  the 
ginger  bread. 

Classification   and    Identification 

These  mental  factors  are  in  turn  aided  by  certain  processes  which 
make  our  perception  even  more  perfect.  One  of  the  normal  in- 
structors met  a  girl  on  the  street  one  day  and  knew  her  to  be  a  normal 
student.  A  few  days  later  he  met  the  same  girl  and  recognized  her 
as  Miss  Smith.  The  first  time  he  classified  her,  and  the  second  time 
he  indentified  her. 

Assimilation  and  Discrimination 

Oh  dear,  some  one  has  put  all  of  our  rubbers  in  one  heap. 
How  will  we  ever  find  our  own?"  This  was  what  1  heard  when 
I  went  into  the  cloak  room  Eventually  however,  everyone  found 
his  own  rubbers.  How  was  this  done?  I  suppose  they  all  found 
theirs  as  I  found  mine.  I  had  certain  fixed  ideas  of  how  my  own 
rubbers  looked.  I  knew  that  they  had  low  heels,  that  they  had  a 
rolled  edge,  that  they  were  new,  and  I  knew  the  size.  By  the  process 

14 


of  assimilation,  I  gathered  all  these  ideas  together  and  finally  recog- 
nized my  own  rubbers.  If  I  picked  up  a  rubber  which  did  not  belong 
to  me,  I  would  know  it  was  not  mine  because  it  had  high  heels  or 
because  of  some  other  difference.  That  is  how  I  discriminated 
mine  from  the  others.  My  perception  in  this  case  was  aided  by  the 
processes  of  discrimination  and  assimilation. 

Summary 

The  above  illustrations  and  examples  show  how  imperfect  our 
perceptions  would  be  if  they  were  not  aided  by  our  mental  factors, 
namely,  knowledge,  imagination,  memory,  habit,  conception,  infer- 
ence and  association. 

We  also  see  how  much  stronger,  clearer  and  more  complete  our 
perceptions  are  when  the  mental  factors  are  aided  by  the  processes  of 
classfication,  identification,  assimilation,  and  discrimination. 


Illusions 

Some  of  our  classmates  were  playing  tennis.  One  stood  waiting 
to  receive  the  ball.  She  raised  her  racket  and  to  the  surprise  of  her 
companions  ran  forward  and  then  stopped  in  the  center  of  the  court, 
looking  surprised.  The  ball  she  was  running  for  was  still  in  the  hand 
of  the  girl  on  the  other  side  of  the  net.  She  had  mistaken  a  sparrow 
for  the  ball.  That  was  an  illusion, ' '  they  told  her.  •  She  had  had 
a  false  perception,  as  was  evident,  and  a  false  perception  is  an  illusion. 

If  we  look  up  *  illusion"  in  our  pocket  dictionaries,  we  may  find 
"hallucination"  as  a  synonym,  but  they  are  not  synonomous. 

Hallucination 

A  business  man  who  frequently  had  telephone  calls  at  night, 
sprang  out  of  bed  one  night,  and  shouted,  "Hello,"  into  the  tele- 
phone which  had  not  rung,  and  was  suprised  to  hear  central  asking 
for  a  number.  His  room-mate  told  him  that  there  had  been  no  call. 
There  was  no  foundation  for  this  mistake,  as  in  the  case  of  the  bird, 
hence  it  was  an  hallucination.  Disordered  minds  frequently  form  hal- 
lucinations. 

15 


Causes  of  Illusions 

A  man  especially  interested  in  birds,  took  his  camera  into  a 
meadow  and  awaited  the  appearance  of  some  birds,  that  had  just  flown 
into  a  clump  of  bushes.  Soon  a  brown  object  flew  up  from  the  bushes 
and  as  he  tried  to  focus  his  camera  on  it,  he  discovered  that  it  was  merely 
a  dried  leaf.  Expectation  caused  this  illusion.  The  man  expected 
to  see  the  birds  fly  from  the  bushes,  and  the  brown  object  moving  in 
a  similar  way  deceived  him. 

One  spring,  many  beautiful  flowers  were  sent  to  a  girl  suffering 
from  a  nervous  breakdown.  Her  windows  were  open,  and  the  gentle 
breeze  caused  the  flowers  to  sway  to  and  fro.  She  noticed  them  and 
thought  that  they  were  faces  of  friends  nodding  to  her.  This  was 
due  to  the  disordered  condition  of  her  mind.  Physical  conditions 
cause  illusions. 

A  member  of  our  class  tried  on  a  pair  of  glasses  which  were 
thicker  on  one  side  of  the  lens  than  the  other.  She  then  tried  to  pick 
a  small  object  quickly  from  the  table,  and  later  from  the  floor.  She 
placed  her  hand  about  ten  inches  from  the  object,  and  then  with  an- 
other movement  succeeded  in  obtaining  it.  The  result  was  the  same 
when  she  tried  to  touch  a  chalk  mark  quickly  with  a  piece  of  chalk; 
her  mark  would  be  at  one  side  of  the  real  mark.  The  longer  she  tried, 
the  nearer  she  came  to  the  real  object.  The  reason  for  this  was  that 
light  always  travels  in  a  straight  line  and  the  uneven  thickness  of  the 
glasses  reflected  the  rays  so  that  the  objects  appeared  at  one  side 
of  their  true  position.  In  correcting  this  illusion  she  reached  to  one 
side  of  where  the  object  appeared  to  be,  and  when  she  took  off  the 
glasses,  recency  of  habit  caused  her  still  to  make  the  correction,  thus 
reaching  the  other  side  of  the  object.  How  many  times  have  you 
looked  into  the  edge  of  a  mirror  and  seen  yourself  with  three  eyes  or 
two  noses?  The  reason  is  that  you  saw  a  reflection  in  the  bevelled  edge 
of  the  glass,  and  another  in  the  mirror  itself.  A  baby  not  used  to  a 
mirror  will  reach  behind  it,  expecting  to  find  another  baby  there. 
External  conditions  cause  these  illusions. 

On  the  first  of  April  a  child  received  a  piece  of  candy.  Biting 
through  the  candy  she  found  it  stuffed  with  cotton.  Because  the  ap- 
pearance was  favorable  she  inferred  that  the  candy  would  taste  good. 
Ho\v  often  inference  causes  illusions. 

16 


We  have  seen  that  illusions  may  be  caused  by  expectation,  habit, 
physical  conditions,  external  conditions  and  inferences. 

Senses  Concerned  with  Illusions 

A  class  mate  tells  me  that  her  small  brother  once  dropped  a 
piece  of  ice  down  her  back,  making  her  think  for  a  few  seconds,  that 
she  was  burned.  The  stimulus  was  so  strong  that  an  illusion  of  touch 
resulted.  A  girl  arriving  home  after  a  nature  walk  declared  that  a  pin 
was  pricking  her  arm,  a  burdock  was  picked  from  her  sleeve,  and  the 
pricking  ceased. 

A  story  is  told  of  a  fraternity  boy  who  awoke  one  night,  and  to  his 
horror  saw7  what  he  thought  to  be  his  roommate  hanging  from  the 
chandelier.  When  he  turned  on  the  light  he  found  only  a  dress  suit. 
It  was  an  optical  illusion  that  made  ffim  mistake  the  suit  for  his  friend. 
Illusions  of  this  kind  are  very  common. 

One  windy  night  one  of  our  class  mates  sat  in  her  room  and 
called  out  "Come  in."  No  one  had  knocked  at  the  door  but  the 
wind  had  rattled  the  window.  A  boy,  whose  name  is  Chester,  thought 
his  father  called  him,  and  answered,  only  to  find  that  his  father  was 
telephoning  and  had  said,  "Yes,  sir."  These  are  illusions  of  hearing. 

A  girl  was  blindfolded  and  had  some  hot  water  and  pepper  put 
on  her  tongue,  she  was  asked  what  it  was  and  promptly  answered, 
"Wintergreen."  The  slight  resemblance  between  the  two  caused 
the  illusion  of  taste. 

Did  you  ever  hear  any  one  say  "I  smell  smoke,"  and  then  go 
in  search  of  the  fire,  when  really  the  odor  came  from  something  near 
at  hand?  This  is  an  olfactory  illusion,  or  one  of  smell. 


Space  Perception 

Space  perception  is  the  ability  to  localize  objects  and  sounds,  to 
judge  size  and  form,  and  to  estimate  distances,  through  the  aid  of  the 
senses  and  certain  mental  factors.  All  the  senses,  with  the  exception 
of  taste,  have  been  found  to  play  some  part  in  space  perception.  These 
senses  are,  namely:  sight,  hearing,  touch  and  smell. 

Sight 

The  normal  students,  knowing  the  directions  from  the  building, 
are  now  able  to  point  out  and  give  the  directions  of  several  places 

17 


when  asked  about  them.  When  these  places  and  their  surroundings 
were  new  to  the  students,  they  were  not  able  to  do  this.  •  They  have 
used  their  power  of  sight  in  the  perception  of  these  new  objects  and 
their  direction. 

A  bird  is  seen  many  feet  away.  Approximately,  with  the  aid  of 
facts  already  stored  up  in  our  minds,  we  are  able  to  perceive  the  exact 
distance  between  ourselves  and  the  bird.  On  the  other  hand,  if  our 
perception  had  been  made  through  the  sense  of  hearing  alone,  we 
would  only  have  known  whether  it  was  quite  a  distance  away.  Our 
sense  of  sight  and  hearing  let  us  know  quite  accurately  where  the  bird 
was. 

One  of  the  members  of  the  class,  who  lives  near  an  observatory 
says  that  she  can  tell  whether  the  people  in  the  observatory  are  chil- 
dren or  adults  by  their  size.  She  knows  what  a  child  looks  like  at  that 
distance,  and  so  uses  her  knowledge  in  her  discrimination.  Magni- 
tude aids  in  estimating  distances  and  the  knowledge  of  distance  aids 
in  rinding  magnitudes. 

Therefore,  sight  is  the  most  important  sense  in  space  perception, 
and  it  is  the  most  accurate  sense.  If  we  perceive  space  through  touch 
or  any  of  the  other  senses  and  we  are  in  doubt  about  our  conclusions, 
we  generally  refer  the  specific  case  to  sight  and  accept  it  as  our  final 
authority.  With  the  knowledge  of  direction  we  may  perceive  with 
the  eye,  almost  correct  locations  of  places. 

Hearing 

A  person  was  blindfolded  and  told  to  point  to,  as  nearly  as  possi- 
ble, the  exact  location  of  a  sound.  The  materials  used  in  making  the 
sounds  were  an  empty  ink  well  and  a  pencil.  It  was  found  that 
sounds  could  be  located  correctly,  in  most  cases,  when  made  on  eith- 
er side  of  the  ear,  but  when  the  sound  was  directly  in  front  or  in 
back,  the  subject  could  not  tell  accurately  at  all. 

There  are  three  different  planes  about  the  ear.  The  first  plane 
passes  at  the  side  of  the  ear.  The  second  plane  passes  in  front  of 
the  ear  and  the  third  plane  passes  above  the  ear. 

The  above  examples  prove  that  sound  vibrations  in  the  first  plane 
are  more  distinct  than  those  in  the  other  planes.  This  may  also  ex- 
plain why  people  turn  their  heads  to  either  side,  in  order  to  hear  better. 

18 


tf  we  are  crossing  the  street  and  hear  the  honk  of  an  automobile 
we  can  tell  from  which  direction  it  is  coming,  and  by  using  our  sense 
of  sight  we  confirm  what  we  have  heard,  and  act  accordingly.  There- 
fore, hearing  and  sight  together  give  us  more  accurate  perceptions  of 
space,  and  the  two  together  save  time. 

Touch 

An  experiment  was  tried  by  touching  the  skin  with  a  wire  hairpin 
First  the  points  were  placed  together  and  then  gradually  separated. 
The  person  was  unable  to  tell  the  two  exact  places  touched  until  they 
were  quite  a  distance  apart. 

Several  persons  were  touched^vith  a  pencil  point  on  their  hands, 
arms,  faces  and  necks.  The  hands  could  locate  the  places  touched 
more  accurately,  and  the  right  hand  did  even  better  than  the  left.  The 
places  touched  on  the  neck  were  not  located  accurately.  This  experi- 
ment proves  that  all  parts  of  the  skin  do  not  produce  the  same  sensa- 
tions, or  in  other  words,  the  same  qualites 

These  experiments  prove  that  we  do  not  perceive  accurately  by 
touch  unless  aided  by  sight. 

Smell 

If  a  hunter  wishes  to  go  very  near  to  a  deer  he  must  go  against 
the  wind.  If  he  should  go  with  the  wind,  the  deer  would  know  that 
he  was  coming  and  get  out  of  his  way  long  before  he  could  see  the 
hunter.  Thus  the  deer,  as  do  many  other  animals,  uses  his  sense  of 
smell  in  perceiving  distance. 

The  hunter  who  is  out  in  the  forest  uses  his  sense  of  sight  and 
hearing  to  find  out  whether  there  is  a  deer  near  him.  He  does  not 
use  his  sense  of  smell  in  order  to  find  the  deer. 

If  a  person  should  smell  smoke  and  could  not  tell  by  using  his 
sense  of  sight  where  it  was  coming  from,  he  would  use  his  sense  of 
smell  to  tell  him  whether  it  was  near  or  far  away.  Thus  the  sense 
of  smell  in  perceiving  distance  is  used  more  by  animals  than  by  people. 

Smell  does  not  play  as  great  a  part  in  space  perception  as  the  sense 
of  sight,  hearing,  and  touch. 


19 


Conditions  Favoring  Perception 

There  are  times  when  a  person  perceives  better  than  at  others  un  • 
der  certain  favorable  conditions.  When  the  physical  conditions  of  an 
individual  are  poor,  his  senses  will  not  be  as  keen  as  they  otherwise 
would  be,  for  all  the  senses  are  affected  by  the  general  health  of  a  per- 
son. These  facts  are  proved  by  the  examples  Driven  under  the  follow- 
ing topics: 

Health 

A  teacher  used  the  blackboard  for  a  great  deal  of  her  work.  A 
little  boy  who  never  had  his  lesson  told  the  teacher  that  he  could  not  see 
the  board.  Finally  it  was  discovered  that  he  had  nearly  lost  his  eye- 
sight, and  had  not  been  able  for  some  time  to  see  the  board.  Thus  he 
was  not  able  to  perceive  by  means  of  his  sight.  A  certain  little  girl 
was  very  backward  in  her  lessons,  and  did  not  appear  to  be  interested 
in  any  way.  Finally  her  parents  took  her  to  a  physician  and  had  her 
examined.  The  doctor  found  that  she  had  adenoids.  After  removing 
them  she  was  a  different  child,  and  became  one,  if  not  the  best  of  the 
scholars  in  her  class. 

If  a  person  eats  a  banana  after  having  his  teeth  extracted,  he 
finds  that  it  does  not  taste  as  it  ordinarily  should,  but  like  some  unknown 
substance.  This  is  probably  due  to  whatever  was  taken  before  having 
the  teeth  extracted,  and  of  course  changes  one's  taste.  One  student 
says:  " After  opening  a  bottle  of  medicine  I  smelled  of  it,  as  I  usually 
do,  to  find  out  its  ingredients,  but  to  my  misfortune,  I  was  unable  to 
smell  anything  because  of  a  bad  cold." 

Intensity  of  Stimulus 

When  the  skin  becomes  extremely  cold  a  warm  object  placed  on 
it  will  give  a  burning  sensation.  A  very  cold  temperature  numbs  the 
skin,  and  pressure  upon  it  at  that  time  cannot  be  felt.  A  cold  object 
feels  larger  than  a  hot  object,  even  though  the  two  be  equal  in  size. 

The  greater  the  intensity  of  the  stimulus  the  greater  the  sensation 
of  touch.  The  sense  of  touch  is  affected  by  the  temperature  and  in- 
tensity of  the  stimulus. 

When  a  person  enters  a  greenhouse  there  are  usually  several 
fragrant  odors,  but  there  is  one  which  prevails  over  all  others,  that  of 
the  carnation.  A  strong,  fragrant  or  pungent  odor  is  more  quickly 
perceived  than  a  light  odor,  and  more  readily  recognized. 

20 


One  day  as  I  stood  on  the  street  waiting  for  a  car,  a  girl  asked 
me  if  I  saw  those  two  normal  students  pass  by  dressed  in  blue  suits. 
I  replied,  "No.''  Then  she  said,  "Did  you  see  that  girl  go  by 
with  that  exceedingly  bright  dress  on?"  "Yes,"  was  my  reply.  I 
began  to  question  myself  as  to  the  reason  that  I  did  not  notice  the 
girls  dressed  in  blue.  I  found  that  the  sense  of  sight  was  greatly  af- 
fected by  the  intensity  of  the  stimulus.  An  exceedingly  bright  object 
will  attract  the  attention  of  one  much  sooner  than  a  dull  object. 

Repetition  and  Frequency 

Repetition  affects  the  se'nse  of  taste.  When  food  is  first  taken 
into  the  mouth,  the  sense  of  taste  is  very  keen.  But  constant  repeti- 
tion dulls  the  sense  of  taste.  Frequency  of  the  stimulus  tires  the  nerve 
endings  to  such  an  extent  that  the  sensations  are  less  easily  felt. 

Frequency  also  affects  the  sense  of  sight,  making  the  person 
more  accurate  with  the  use  of  that  organ.  In  looking  at  a  picture 
for  the  first  time  we  see  only  the  general  outline,  but  on  seeing  it 
again  we  notice  the  details,  and  so  on  until  the  very  minute  points  of 
the  picture  are  recognized. 

Attention 

When  a  student  is  studying  a  lesson  in  the  same  room  where 
other  students  are  conversing  it  will  take  him  much  longer  to  prepare 
his  lesson  than  it  would  if  he  had  been  alone. 

If  a  person  concentrates  his  mind  on  any  subject  he  will  become 
acquainted  with  it  more  quickly  than  when  his  mind  is  taken  up  with 
two  or  three  other  things. 

Atmospheric  Conditions 

On  a  day  when  the  air  is  very  heavy  the  childern  are  very  restless 
and  difficult  to  control,  while  on  a  pleasant  day  they  are  usuallv  very 
quiet.  Therefore  atmospheric  conditions  in  the  room  affect  pupils 
and  teachers.  Children  going  to  school  on  a  day  that  the  air  is  very 
heavy  often  are  unable  to  see  the  schoolhouse,  but  can  hear  the  bell. 


Development  of  Perception 

Perception  plays  such  an  important  part  in  the  life  of  every  indi- 
vidual that  it  should  be  developed  to  its  fullest  extent. 

21 


The  difference  between  a  child  and  a  man  in  their  ability  to  peri  eive 

is  that  a  child  is  just  beginning  to  develope  his  powers  of  perception, 

while  the  man  by  association  and  experience  has  developed  his  powers 

to  a  greater  extent,  so  that  he  is  able  to  adapt  himself  to  his  surroundings. 

The  Use  of  Objects  as  an  Aid  to  Perception 

A  child  was  given  a  block  to  play  with.  He  looked  at  it,  pounded 
it,  tasted  it,  and  brought  every  sense  into  action  until  he  knew  it.  If 
the  block  had  been  placed  in  a  different  position  he  would  have  still 
recognized  it  as  the  same  block,  although  its  appearance -was  changed. 

Harry,  one  and  one-half  years  of  age,  w?as  given  a  small  cart  at 
Christmas  time.  He  had  never  seen  a  cart  before,  but  now  he  had 
one  of  his  own.  The  boy's  father  was  very  much  interested  in  Psy- 
chology and  noticed  the  development  of  the  child's  perception.  By 
observation  the  boy  had  formed  a  usual  image  of  the  cart,  by  touch 
he  perceived  that  it  was  hard,  and  by  drawing  it  across  the  floor,  he 
noticed  that  a  noise  was  made.  Thus  through  the  senses  the  various 
characteristics  of  the  cart  were  perceived.  Soon  after  the  child  saw 
one  of  his  little  friends  pulling  a  toy.  He  called  it  a  cart  because  it 
looked  like  his,  and  was  used  the  same  as  his  toy.  The  boy  formed 
a  general  class  for  carts,  having  to  a  certain  extent,  the  characteristics 
of  his  own  toy.  Thus  assimilation  aids  one  in  perceiving  classes  of 
objects. 

Later  the  boy  learned  that  there  were  many  types  of  vehicles 
classed  as  carts.  By  discrimination  he  was  able  to  recognize  the  in- 
dividual from  the  class. 

Richard,  a  very  small  child,  was  given  a;  kitten  to  play  with.  He 
became  very  fond  of  the  pet.  One  day  when  playing  out  of  doors, 
he  saw  a  caterpillar  crawling  along  the  walk.  He  ran  into  the  house 
and  said  to  his  mother:  "See  the  pretty  kitten  I  found  out  there  on 
the  walk."  He  had  placed  both  objects  in  the  same  class  because  he 
noticed  the  fur  on  each  and  thought  they  looked  alike.  After  his 
mother  explained  the  differenres  between  the  tw7o  objects  he  was  able 
to  recognize  the  class  of  caterpillars  from  the  class  of  kittens.  Al- 
though the  child  could  classify  kittens  or  caterpillars  he  would  not  know 
the  particular  general  species  of  kitten  or  caterpillar.  Many  times  the 
class  mirne  for  objects  is  known,  although  its  individuals  of  the  class 
cannot  be  identified. 

22 


A  boy  had  just  entered  school.  He  knew  many  words  but  had 
not  learned  to  read.  He  learned  words  by  rote  and  later  was  able  to 
recognize  them  by  sight.  Soon  he  was  able  to  think  out  words  for 
himself  because  he  found  some  familiar  characteristic  in  the  new  words. 
For  example  the  boy  knew  the  word  "rat"  and  was  able  to  make  out 
the  word  "mat*'  by  recognizing  the  known  phonic  and  adding  it  to 
the  first  sound. 

By  assimilation  the  boy  was  able  to  recognize  the  sound  "at"  in 
both  words.  By  discrimination  he  was  able  to  notice  that  the  first 
letter^  were  not  alike  and  as  he  knew  the  sound  of  "m"  he  was  able 
to  make  the  new  word.  <• 

A  little  girl  was  walking  with  her  sister.  She  stopped  and  plucked 
a  flower.  "See  my  lovely  flower, "she  said.  The  sister  asked  the 
color  of  the  petals,  but  the  child  could  not  tell.  If  the  child  had  pre- 
viously studied  the  flower  and  analyzed  its  parts  she  would  have  noticed 
its  color,  petals,  stem, etc. ,  and  would  have  been  able  to  answer  her 
sister's  question. 

A  man  entered  a  store,  tasted  some  coffee,  and  immediately  stat- 
ed the  grade  to  which  it  belonged.  His  perception  of  coffee,  many 
years  previous,  was  that  of  an  ordinary  person,  its  pleasing  taste.  By 
observation  and  practice  he  was  able  to  associate  various  tastes  to  special 
grades  of  coffee.  Special  training  along  that  line  had  made  his  per- 
ceptions strong  and  accurate. 

The  children  in  a  certain  class  were  drawing  and  coloring  pictures 
of  toys  which  were  to  be  placed  on  a  calender  to  be  taken  home. 
The  children  noticed  the  size,  shape  and  color  of  the  toys  and  were 
very  careful  with  their  work,  because  they  were  doing  it  for  a  special 
purpose.  Sense  discrimination  may  be  improved  if  it  is  involved  in 
gaining  some  specific  end  or  purpose. 

There  are  so  many  ways  by  which  our  perceptions  are  developed, 
that  it  is  well  for  us  to  choose  the  most  beneficial  and  accurate  aids  in 
order  that  our  general  knowledge  may  be  of  a  helpful  nature. 

The  important  aids  to  the  development  of  perception  are  these: 
assimilation,  discrimination,  association,  special  training  and  study,  and 
specific  purpose. 

23 


Apperception 

We  have  found  that  only  very  young  children  have  pure  sensations. 
These  sensations  leave  perceptions  and  ideas  in  the  mind.  When  the 
number  becomes  great  enough  we  begin  to  classify  them,  and  each 
new  sensation  and  idea  is  classified  and  connected  with  something  old. 

For  example,  a  child  has  seen  a  great  many  square  tables.  When 
he  sees  a  round  table  he  groups  the  new  perception  with  the  old  and 
knows  that  this  new  object  is  also  a  table.  This  grouping  of  old  ideas 
with  new  ideas  to  gain  new  perceptions  is  called  apperception. 

The  relation  of  the  words  perception  and  apperception  in  form 
suggest  their  meaning.  Apperception  is  perception  carried  further. 
Perception  and  apperception  are  so  closely  related  that  it  is  difficult 
to  tell  where  one  stops  and  the  other  begins.  The  main  difference  is 
that  in  perception  the  mind  gains  perceptions  through  the  senses.  In 
apperception  the  mind  is  active  and  by  means  of  attention  groups  the 
old  ideas  so  as  to  form  new  ones. 

It  has  already  been  mentioned  that  if  one  hand  is  placed  in  hot 
water  and  the  other  in  cold  water  and  then  both  are  placed  in  luke 
warm  water,  the  water  feels  cold  to  one  and  warm  to  the  other,  re- 
spectively. This  is  due  to  the  different  previous  experience  of  the 
two  hands.  The  mind  acts  in  the  same  way.  The  same  sensation 
or  stimulus  will  produce  different  results  in  minds  that  have  had  differ- 
ent experiences  and  masses  of  ideas. 

This  is  well  illustrated  by  an  example  taken  in  a  class  of  normal 
students.  Four  students  were  asked  to  answer  a  question.  The  ques- 
tion was  the  same  to  all  four,  "What  was  the  result  of  the  con- 
test?" The  first  girl  answered,  "The  Clinton  girls  won."  The 
second  reply  was,  "The  Athletics  won  the  final  one."  The  third 
replied,  "The  Overland  finished  with  the  best  score,"  while  the 
fourth  girl  stated,  "Miss  B —  won  the  first  prize."  The  first  girl  was 
captain  of  the  girls'  basket  ball  team.  The  second  was  a  base  ball 
"fan, "and  referred  to  the  recent  "World's  Series."  The  third  one 
questioned  was  an  ardent  automobilist  and  referred  to  an  endurance 
test.  The  fourth  girl  was  interested  in  elocution  and  referred  to  the 
result  of  a  recent  prize-speaking  contest.  The  word  "contest"  called 
up  different  ideas  because  of  different  previous  experiences. 

24 


Two  men  standing  on  the  street  corner  observed  a  friend  board- 
ing a  street  car  with  a  suit  case  in  his  hand.  "Evidently  Jones  is  go- 
ing on  a  vacation, "remarked  the  first.  "No,  I  think  he  is  going  to 
the  wash  woman's  with  his  clothes.  This  is  Monday,  you  know," 
replied  the  second.  The  latter  had  been  in  the  habit  of  going  to  the 
laundry  on  Monday. 

Summary 

What  one  will  perceive  will  depend,  therefore,  on  his  nature 
and  stock  of  ideas,  or,  in  other  words,  his  character,  habits,  memory, 
education,  previous  experience  and  momentary  mood. 

Apperception,  or  association  of  ideas,  is  of  great  importance  in 
teaching.  It  is  back  of  the  familiar  recommendation,  "proceed  from 
the  known  to  the  unknown."  A  good  teacher  always  considers  pre- 
ious  experience  and  the  present  state  of  the  pupil's  mind  when  pre- 
paring a  new  lesson. 

Sometimes,  in  beginning  a  new  lesson,  a  teacher  asks  a  great 
many  simple  questions  which  every  member  of  the  class  is  able  to 
answer.  This  seems  a  waste  of  time,  but  is  really  necessary  to  se- 
cure the  proper  state  of  mind  for  the  new  lesson. 

Good  teaching  consists  in  fitting  the  stimuli  to  the  child's  knowl- 
ledge  for  the  purpose  of  adding  to  it.  We  must  not  only  start  with 
the  known,  but  also  proceed  to  the  unknown  as  well.  To  simply 
elaborate  the  review  is  a  violation  of  the  laws  of  apperception  that  is 
worse  than  to  give  facts  that  cannot  be  understood. 


25 


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